Is flexeril a tricyclic/H1 antihist?  I have a lot of neuromuscular problems when I flare up.  I found that newer muscle relaxers didn't seem to help, but flexeril does and wondered if it is partially due to antihist effects.

A couple of months ago I started having terrible muscle spasms that at times resembled partial seizures. I searched and found the Ehlers Danlos group had a discussion about pseudoseizures that fit the description. It was during a very stressful (high tension) time. I have HEDS & MCAS.
But I tried skelaxin that I'd had for some time and it did nothing. I then found 10 flexiril from a car accident 3.5 years ago where I filled the prescription but didn't use it.
I took a half of one each night and actually was able to sleep for the first time in days. It is the only thing I've found to work. But I only have a few left so have hardly used them.
I was doing better the last few weeks with just the occasional jerk or twitch and what looks like chills going down my back though it's not the same feeling as when you get the chills. I feel pressure build up in my spine and I may gasp or moan just before the spasms or 'chills' hit. It had almost stopped and I took a 'sleep aid' the other night. It said non-habit forming, safe, etc. I didn't realize it's the same as benadryl. I take a tiny (5mg) dose of benadryl almost every day and a few times some days. I took this sleep aid and it was 50 mg of benadryl!! I started hurting so bad. I went into the spasms again - my whole body was shaking violently for about 3 seconds at a time. It went on about an hour and I then I collapsed and slept hard.
I take no other medications but I do take magnesium and a few other things.
Anyway that is my experience and I don't quite know what to make of it. I may ask for some more flexiril though. I didn't seem to have any side effects but then I was asleep.